Meta-analysis of Functional Magnetic Resonance Imaging Studies of Inhibition and Attention in Attention-deficit/Hyperactivity Disorder:  Exploring Task-Specific, Stimulant Medication, and Age Effects

Figure 1. Inhibition tasks and attention tasks. A, All inhibition tasks together. Regions of decreased (red and orange) and increased (blue) activation in patients with attention-deficit/hyperactivity disorder compared with healthy controls. Decreased activation in patients with attention-deficit/hyperactivity disorder relative to healthy controls is shown in the right inferior prefrontal cortex (IFC) extending into the insula, in a cluster comprising the supplementary motor area (SMA) and the cognitive division of anterior cingulate cortex (ACC), in the left caudate extending into the putamen and insula, and in the right mid-thalamus. B, Attention tasks. Decreased activation in patients with attention-deficit/hyperactivity disorder is shown in the right dorsolateral prefrontal cortex (DLPFC), in the left putamen and globus pallidus, in the right posterior thalamus (pulvinar) and caudate tail extending into the posterior insula, in the right inferior parietal lobe, and in the precuneus and superior temporal lobe. Increased activation in patients with attention-deficit/hyperactivity disorder relative to healthy controls was seen in the left cuneus and in the right cerebellum.

Figure 2. Inhibition tasks. A, All inhibition tasks together, with cross sections showing regions of decreased activation in patients with attention-deficit/hyperactivity disorder compared with healthy controls. Shown are the right inferior prefrontal cortex, insula, right thalamus, left caudate, left putamen, and left insula. B. Motor response inhibition only, showing the right inferior prefrontal cortex and insula, right supplementary motor area and anterior cingulate cortex, right thalamus, left caudate, and right fusiform gyrus. C, Interference inhibition only, showing the right inferior prefrontal cortex and insula, left anterior cingulate cortex, right caudate (head), and left posterior parietal lobe and posterior insula. The right side of the image corresponds to the right side of the brain. Distance from the anterior or posterior commissure is indicated in millimeters for the z coordinate.

Figure 3. Results of the meta-regression analysis with stimulant medication effects for attention. Meta-regression analysis for attention shows that the percentage of patients receiving long-term psychostimulant treatment is associated with more normal right caudate activation relative to healthy controls. The regression line (meta-regression signed differential mapping slope) is presented as a straight line.

Figure 4. Age group analysis for regions that differed in patients with attention-deficit/hyperactivity disorder relative to healthy controls during inhibition shows that the reduced activation in the supplementary motor area (SMA), in the left putamen and globus pallidus, and in the right caudate was abnormal only in children with attention-deficit/hyperactivity disorder relative to their age-matched healthy controls, while the reduced activation in the right inferior prefrontal cortex (IFC) and in the right thalamus was significant only in adults with attention-deficit/hyperactivity disorder relative to their age-matched healthy controls. B indicates bilateral.